Does the record cold winter mean global warming is a myth? Auburn climatologist weighs in on climate change controversy

The winter of 2013-14 was the coldest since 1977 and snowiest since 1982, according to the National Weather Service in Birmingham. Seen here, vehicles on Interstate 20 east of Brompton are are stuck due to slippery roads. (Joe Songer/Alabama Media Group)

BIRMINGHAM, Alabama -- There's no denying that it's been an unusually cold and snowy winter in Alabama.

According to the National Weather Service in Birmingham, the last time average winter temperatures fell this low was in 1977.

And the last time an Alabama winter produced 5 inches of snowfall -- recorded at the Birmingham airport -- was in 1982, excluding the the ice storm of 1993, which technically occurred in the spring.

"It's clearly above average snowfall. We're talking top 10 percent," said Aaron Gleason, a meteorologist with the NWS in Birmingham.

But what does the unusual weather say about what has become perhaps the most politicized and debated meteorological phenomenon of the 20th century?

At first glimpse, the extreme weather suggests that what scientists initially called global warming and now tend to refer to as global climate change is in fact a myth, debunked by the record cold temperatures this winter.

Compared to the normal average temperature for a Birmingham winter of 46 to 47 degrees since the weather service started keeping records in 1896, this winter's average temperature of 43.1 degrees kind of undercuts the whole warming part of global warming.

But for a climatologist at Auburn University, the unprecedented wintery weather is just mounting evidence that global warming is occurring and that more extreme weather could be on its way.

In a recent interview with AL.com, Chandana Mitra, an assistant professor specializing in climatology at Auburn University, said not only that the cold weather does not disprove global warming, but that it could be the cause of the extreme winter conditions -- though she admits the theory is not yet proven.

If you watch The Weather Channel, you probably already know that temperatures plummeted when a system of strong, upper level winds known as the Polar Vortex shifted south from the North Pole and covered much of the continental United States.

According to Mitra, the Polar Vortex is not a new phenomenon, occurring every year as the planet's poles experience decreasing levels of sunlight during the winter.

The difference this year, she said, is that the Jet Stream, which normally bottles the Polar Vortex in the Arctic, dipped far south to Mexico, allowing the frigid air to spill across the continental United States.

Like the Polar Vortex, the Jet Stream is a system of fast, upper level winds. It is powered by the temperature difference between the Arctic and middle latitudes across the globe.

According to the Intergovernmental Panel on Climate Change, the
average global temperature climbed 0.85 degrees between 1880 and 2012.

But Mitra says researchers have also discovered that the poles are warming substantially faster than the rest of the plant.

She says scientists theorize that as the temperature difference between the arctic and the lower latitudes declines the Polar Vortex will move south more frequently, subjecting some regions to unusually cold weather.

"The Jet Stream will weaken and is going to have a tendency of coming south," Mitra said. "So we may see more of these extreme events happen in the future if the temperature difference between the arctic and lower latitudes is reduced."

Does that mean Alabamians should invest in tire chains and snow plows before next winter? Not at all, says Mitra.

"We can't base any kind of scientific theory on just one weather event. We have to wait and see if extreme weather events like this occur more frequently in the near future. Then we can pass judgement."

Additionally, Mitra says global warming affects different regions of the globe in different ways, making it more difficult to observe the cause and effect.

Comparing Earth's global warming to a human running a high fever, Mitra says the impact of rising temperatures in oceans and the atmosphere could be flooding in some places, poor crops in others, increased disease outbreaks in various regions and other extreme events.

"We really have to go local to regional to global and vice versa to see the changes and understand the complexities of the Earth's systems," she said.

"Most scientists who are doing the research are reporting that the number of extreme events will increase."

Whatever the case, Mitra says one cold winter is not enough to disprove global warming. She notes that at the same time Alabama was frozen over, parts of Australia, Asia, Russia and even Alaska were seeing record warm temperatures.

"If we're saying global warming is a myth because it's cold, are Alaskan people saying global warming is real because it's unexpectedly warm ... in the middle of the winter season?" she asked.